1. Field of the Invention
Embodiments relate to a method of manufacturing a semiconductor device and, more particularly, to a method of manufacturing a semiconductor device having an even coating thickness using electro-less plating, and a device made thereby.
2. Description of the Related Art
Generally, electroplating and electro-less plating may be used to deposit a material layer, e.g., a conductive layer, on a substrate. Electroplating typically involves exposing a target substrate to a metal-containing solution, in which metal ions are dissolved in acid, and driving a reduction reaction using an applied electric potential so as to convert the metal ions to a metal layer on the substrate. For example, the substrate may be immersed in the metal-containing solution while being connected as a cathode of the electrical circuit. The cathode may be connected to a first pole of a power source, and an anode connected to an opposite pole of the power source may be immersed in the solution to complete an electrical circuit.
Unlike conventional electroplating, electro-less plating does not depend on the application of an external electrical potential to drive the plating process. Electro-less plating may be a desirable alternative to electroplating, because the relatively simple electro-less plating process may require less equipment and lower costs as compared to electroplating. Further, electro-less plating may be employed to form a metal layer on sidewalls and a top portion of a bump, whereas electroplating may form a metal layer only on the top portion of the bump.
It is commonly understood that even non-conductive substrates may be plated using electro-less plating, i.e., conductivity of the substrate is not required. However, where finely-patterned features are to be plated using electro-less plating, a difference in electrical potential between similar features formed on the substrate may result in those features being unevenly plated. Thus, in the fabrication of a semiconductor device having finely-patterned features such as, e.g., bumps, wiring patterns, etc., variations in plating thickness may occur when using an electro-less plating process, and the variations in plating thickness may reduce the reliability of the semiconductor device.